Products
Norfloxacin is commercially available in the form of film-coated tablets. It was approved in many countries in 1983. The original product, Noroxin, is no longer available, but generics are available.
Structure and properties
Norfloxacin (C16H18FN3O3, 319.33 g/mol) is a fluoroquinolone. It exists as a white to pale yellow, hygroscopic, photosensitive crystalline powder that is very sparingly soluble in water.
Effects
Norfloxacin (ATC J01MA06) has bactericidal properties against Gram-positive and Gram-negative pathogens. The effects are due to inhibition of bacterial DNA gyrase (topoisomerase II) and topoisomerase IV.
Indications
For the treatment of bacterial infectious diseases with susceptible pathogens, e.g., urinary tract infections.
Dosage
According to the SmPC. Tablets are taken fasting, at least one hour before or two hours after meals.
Contraindications
- Hypersensitivity, including to chemically related quinolones.
- Anuria
- Children under 18 years
- Pregnancy and lactation
- Combination with tizanidine (substrate of CYP1A2).
Full details of precautions and interactions can be found in the drug label.
Interactions
Norfloxacin is an inhibitor of CYP1A2 and may cause appropriate interactions with substrates of the isoenzyme. Other drugs, particularly minerals, iron, zinc, sucralfate, didanosine, and antacids, as well as milk, should not be administered at the same time but at least two hours apart because they may reduce the absorption of norfloxacin. Other interactions have been described (see [FI).
Adverse Effects
The most common possible adverse effects include nausea, loss of appetite, diarrhea, taste disturbances, bitter taste, and other digestive symptoms, depression, sleep disturbances, nervousness, anxiety, headache, dizziness, sensory disturbances, blood count disturbances, rash, seizures, and vaginal thrush. Norfloxacin may make the skin sensitive to sun and rarely cause liver inflammation and tendonitis or tendon rupture. Other less common side effects are observed. The skin should be protected from excessive sun and UV radiation during treatment.
